Liverpool youngster Neco Williams’ goal was his second for WalesWales marked Gareth Bale's 100th cap with a thumping victory over Belarus to move up to second place in their World Cup qualifying group.
Aaron Ramsey's rebound put Wales ahead in the second minute before Bale set up Neco Williams to score with a low shot which Belarus keeper Sergei Chernik should have saved.
With Bale taken off at half-time as he made his first appearance after two months out injured, Ramsey extended the hosts' lead with a second-half penalty.
Ben Davies scored his first international goal as his attempted header went in off his shoulder and, after Artem Kontsevoi whipped in a superb 20-yard strike for Belarus, Connor Roberts flicked in from a free-kick for Wales' fifth.
Wales are now second in Group E, three points ahead of the third-place Czech Republic, who will be expected to beat Estonia on Tuesday.
However, notional Welsh hopes of qualifying automatically are officially over after Belgium beat Estonia to win the group.
Wales are already guaranteed a play-off place having won their Nations League group last year but, to have any chance of a home draw, they must finish second in their World Cup qualifying group.
Robert Page's men can secure second spot on Tuesday with a draw at home to Belgium. That will be difficult, though Wales can take heart from the fact they have won two of their past three matches against the world's number one-ranked side.
And in Bale they will have a figurehead who played a vital role in one of those victories, scoring the winning goal in a European Championship qualifier when Belgium were last in Cardiff.
Wales' celebrate Bale's hundred in style
Bale' milestone gave this game a sense of significance that would ordinarily have been lacking for the visit of a team of Belarus' standing.
This was a celebration of Wales' greatest footballer, a national hero who has taken his country to new heights over the course of a stellar 16-year career.
True to his obsessive professionalism, Bale had played down the fanfare in the build-up to the match. Only after the game would he consider reflecting on his achievement; victory against Belarus was his sole focus.
His wish was his team-mates' command, with Wales racing into an early lead to delight an already jubilant Cardiff City Stadium crowd.
After Belarus failed to properly clear a corner, Davies hit a sweet volley almost straight Chernik, who spilled the ball into Ramsey's path for a tap-in.
There was worse to come from the Belarus keeper as he palmed Williams' low shot into the net.
With a 2-0 lead and Belarus offering little threat, Bale was taken off at half-time as a precaution with the Real Madrid forward playing for the first time since tearing his hamstring in September.
As a result, he passed the captain's armband and penalty-taking duties to Ramsey, who punished Ruslan Yudenkov's handball by sending Chernik the wrong way from the spot.
Davies was the next to score with a rather scruffy effort off his shoulder from Harry Wilson's corner and, although Kontsevoi's rocket gave Belarus a late reason to cheer, Wales had the final say as Roberts deftly volleyed in at the near post from a free-kick.
Wales on course for second place
While the safety net of a guaranteed play-off place had alleviated the pressure on Wales, they were determined to do all they could to improve their chances of a home draw in March.
With the play-off semi-finals and finals played over one leg, Page and his players would rather avoid an away game against teams such as Switzerland and Serbia, who are among those in a strong position to secure the seeding required for home advantage.
Beating Belarus was imperative and, having been held to a frustrating home goalless draw by Estonia in September, Wales were desperate to avoid another anxious evening.
Their clinical performance made sure of that, scoring more than four goals in a game for the first time since their 6-0 thrashing of China in March 2018, when Bale's hat-trick made him Wales' all-time leading goalscorer.
The winning margin against Belarus is also helpful. If Wales and the Czech Republic end on the same amount of points, second place will go to the team with the best goal difference or, failing that, the team with most goals scored. Wales currently have a goal difference two better than the Czechs, having scored one goal more in total.
Wales will hope that they will not need to rely on such criteria. Their destiny is in their own hands: secure at least a draw against Belgium on Tuesday and second place is theirs.
Line-ups
Wales
Formation 4-4-2
12Ward
15Ampadu6Rodon4Davies3N Williams
14Roberts10Ramsey7Allen8Wilson
11Bale20James
12WardSubstituted forHennesseyat 90+1'minutes15AmpaduBooked at 59mins6Rodon4Davies3N Williams14Roberts10RamseySubstituted forMorrellat 71'minutes7Allen8Wilson11BaleSubstituted forJohnsonat 45'minutes20JamesSubstituted forRobertsat 76'minutesSubstitutes
1Hennessey2Gunter5Mepham9Roberts13Colwill16Morrell17Thomas18M Harris19Vaulks21Davies22Johnson23WilliamsBelarus
Formation 3-5-2
1Chernik
3Shvetsov4Naumov6Yudenkov
13Zolotov21Klimovich14Yablonski8Selyava2Pechenin
18Sedko17Lisakovich
1Chernik3Shvetsov4Naumov6YudenkovSubstituted forKontsevoyat 82'minutes13ZolotovBooked at 25minsSubstituted forYuzepchukat 71'minutes21KlimovichSubstituted forEbongat 71'minutesBooked at 83mins14Yablonski8Selyava2Pechenin18SedkoSubstituted forAntilevskiat 60'minutesBooked at 78mins17LisakovichSubstituted forBakharat 81'minutesSubstitutes
5Shevchenko7Sokol9Ebong10Bakhar11Solovey12Khatkevich15Yuzepchuk16Pavlyuchenko19Kontsevoy20Lisakovich22Levitskiy23AntilevskiLive Text
Match ends, Wales 5, Belarus 1.
Second Half ends, Wales 5, Belarus 1.
Joe Morrell (Wales) wins a free kick in the defensive half.
Foul by Ivan Bakhar (Belarus).
Substitution, Wales. Wayne Hennessey replaces Danny Ward.
Goal! Wales 5, Belarus 1. Connor Roberts (Wales) right footed shot from the right side of the six yard box to the top right corner. Assisted by Harry Wilson with a cross following a set piece situation.
Connor Roberts (Wales) wins a free kick on the right wing.
Foul by Kirill Pechenin (Belarus).
Goal! Wales 4, Belarus 1. Artem Kontsevoy (Belarus) right footed shot from outside the box to the top right corner. Assisted by Evgeni Yablonski.
Attempt saved. Ivan Bakhar (Belarus) header from the centre of the box is saved in the top centre of the goal. Assisted by Kirill Pechenin with a cross.
Attempt saved. Ben Davies (Wales) left footed shot from the centre of the box is saved in the bottom right corner. Assisted by Harry Wilson with a cross.
Max Ebong (Belarus) is shown the yellow card for a bad foul.
Tyler Roberts (Wales) wins a free kick on the left wing.
Foul by Max Ebong (Belarus).
Substitution, Belarus. Artem Kontsevoy replaces Ruslan Yudenkov.
Substitution, Belarus. Ivan Bakhar replaces Vitali Lisakovich.
Foul by Brennan Johnson (Wales).
Ruslan Yudenkov (Belarus) wins a free kick in the defensive half.
Attempt blocked. Joe Allen (Wales) right footed shot from outside the box is blocked. Assisted by Joe Morrell.
Harry Wilson (Wales) wins a free kick in the attacking half.
